Pencil is an animation/drawing software.

It lets you create traditional hand-drawn animation (cartoon) using both bitmap and vector graphics. Pencil is free and open source.

What’s new in this version:

* improved performance for playback
* camera layers
* redesigned interface and icons
* possibility to import several bitmap files by drag and drop
* copy and paste between Pencil and other applications (clipboard)
* possibility to import and export colour palettes
* possibility to rename layers and colours
* possibility to adjust colours and alpha
* possibility to reduce the scrub
* improved brush tool (bitmap mode)
* added a specific tool for editing curve points
* added feather for invisible curves (experimental)
* remembers palette positions
* source code has been unified for Mac, Windows, and Linux
* now available on sourceforge SVN repository
* fixed bug 1730904 and many others (thanks to Mark Schmelzenbach)
* fixed tablet support on Windows?? (thanks to Mark Schmelzenbach)
* added Aqua style option on Mac

Website
Download Pencil